This save is as complete as a save can get I think, I hope.
It's got all items (in storage mostly) or at least I think it has (no cheats used what so ever) and it's capable of doing any ending (I've saved it just before you fight the last boss and if you want to go on to do the true endings you can) and has also got the chaos dungeon complete too.
If you want 100% gallery unlock just complete the save (True ending, ending G) and get the unlocked gallery. I used this walk through. If I've missed anything feel free to let me know.